A light modulating device in related art generally includes an entrance slit, a collimating part, a dispersion assembly, a focusing part, and the like. Since the light modulating device has many components independently arranged, its volume is usually too large, and an operating environment of the light modulating device is limited. It can be used in a laboratory or other spacious environment, but cannot be used in a narrow and small space. Therefore, an application scope of the light modulating device is limited.
In addition, silicon wafers or other organic materials are generally used for fabricating collimating parts, dispersion assembles, and the like for known light modulating devices. However, organic materials such as silicon wafers are relatively expensive, thereby increasing a fabricating cost of the light modulating device.